Multichannel fluctuating field approach to competing instabilities in interacting electronic systems
(2023) In Physical Review B 108(3).- Abstract
Systems with strong electronic Coulomb correlations often display rich phase diagrams exhibiting different ordered phases involving spin, charge, or orbital degrees of freedom. The theoretical description of the interplay of the corresponding collective fluctuations giving rise to this phenomenology, however, remains a tremendous challenge. Here, we introduce a multichannel extension of the recently developed fluctuating field approach to competing collective fluctuations in correlated electron systems. The method is based on a variational optimization of a trial action that explicitly contains the order parameters of the leading fluctuation channels. It gives direct access to the free energy of the system, facilitating the distinction... (More)
Systems with strong electronic Coulomb correlations often display rich phase diagrams exhibiting different ordered phases involving spin, charge, or orbital degrees of freedom. The theoretical description of the interplay of the corresponding collective fluctuations giving rise to this phenomenology, however, remains a tremendous challenge. Here, we introduce a multichannel extension of the recently developed fluctuating field approach to competing collective fluctuations in correlated electron systems. The method is based on a variational optimization of a trial action that explicitly contains the order parameters of the leading fluctuation channels. It gives direct access to the free energy of the system, facilitating the distinction between stable and metastable phases of the system. We apply our approach to the extended Hubbard model in the weak to intermediate coupling regime where we find it to capture the interplay of competing charge density wave and antiferromagnetic fluctuations with qualitative agreement with more computationally expensive methods. The multichannel fluctuating field approach thus offers a promising route for a numerically low-cost treatment of the interplay between collective fluctuations in small to large systems.
(Less)
- author
- Linnér, E. ; Lichtenstein, A. I. ; Biermann, S. LU and Stepanov, E. A.
- organization
- publishing date
- 2023-07-15
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Review B
- volume
- 108
- issue
- 3
- article number
- 035143
- publisher
- American Physical Society
- external identifiers
-
- scopus:85166741077
- ISSN
- 2469-9950
- DOI
- 10.1103/PhysRevB.108.035143
- language
- English
- LU publication?
- yes
- id
- b087e5a3-23ff-4e73-ab35-d616217b1098
- date added to LUP
- 2023-12-20 13:26:31
- date last changed
- 2025-04-04 15:15:24
@article{b087e5a3-23ff-4e73-ab35-d616217b1098,
abstract = {{<p>Systems with strong electronic Coulomb correlations often display rich phase diagrams exhibiting different ordered phases involving spin, charge, or orbital degrees of freedom. The theoretical description of the interplay of the corresponding collective fluctuations giving rise to this phenomenology, however, remains a tremendous challenge. Here, we introduce a multichannel extension of the recently developed fluctuating field approach to competing collective fluctuations in correlated electron systems. The method is based on a variational optimization of a trial action that explicitly contains the order parameters of the leading fluctuation channels. It gives direct access to the free energy of the system, facilitating the distinction between stable and metastable phases of the system. We apply our approach to the extended Hubbard model in the weak to intermediate coupling regime where we find it to capture the interplay of competing charge density wave and antiferromagnetic fluctuations with qualitative agreement with more computationally expensive methods. The multichannel fluctuating field approach thus offers a promising route for a numerically low-cost treatment of the interplay between collective fluctuations in small to large systems.</p>}},
author = {{Linnér, E. and Lichtenstein, A. I. and Biermann, S. and Stepanov, E. A.}},
issn = {{2469-9950}},
language = {{eng}},
month = {{07}},
number = {{3}},
publisher = {{American Physical Society}},
series = {{Physical Review B}},
title = {{Multichannel fluctuating field approach to competing instabilities in interacting electronic systems}},
url = {{http://dx.doi.org/10.1103/PhysRevB.108.035143}},
doi = {{10.1103/PhysRevB.108.035143}},
volume = {{108}},
year = {{2023}},
}